If you had a nitrided (or whatever the particular manufacturer calls it) barrel you probably could polish it up to a shine, they're smoother and shinier to begin with, and it's not a surface coating that will come off. Regular parkerized barrels are so rough I don't see it happening, and if you did it would probably rust easy where the nitrided should not.
I've seen people doing just this with Glock slides and barrels, not my thing at all but it can be done!